Smoke and flames are seen from the air at the Chiwaukum Creek Fire near Leavenworth, Wash., Thursday, July 17, 2014.

Ted S. WarrenAP Photo

Residents of 860 homes have been told they should evacuate as a wildfire burns out of control in central Washington state.

The Chiwaukum Creek fire in Chelan County, believed to have been started by lightning and first detected on Tuesday, remains zero percent contained. It has now burned approximately 4,500 acres.

The blaze, which is about 10 miles north of Leavenworth, has closed 35 miles of U.S. Highway 2. It is burning through heavy timber in the alpine area.

On Wednesday, it sent a smoke plume 25,000 feet into the air that was visible for miles.

"There's a huge cloud of smoke above us," Don Hurst, a retired firefighter who lives just outside of Leavenworth, told The Associated Press. "It's just like snowfall here with the ash coming down."

The fire is one of three making up the Mills Canyon Complex, which a total of nearly 1,000 firefighters are combating. The Mills Canyon fire, the state's largest at 35 square miles, is 40 percent contained.

Wildfires are raging across several western states. Oregon Gov. John Kitzhaber, a Democrat, declared a state of emergency on Wednesday, which allows the National Guard to mobilize resources as needed to help fight the fires.

A state of emergency covers much of eastern Washington. Continued heat and wind gusts of up to 30 mph were forecast for Thursday.